Cobalt(II)-M-hexacyanoferrate(II), M = K, NH4, Cs, as synthetic sorbents have ion exchange properties selective for monovalent cations. They show a higher selectivity for the ions with larger crystal radius if the sorption takes place in dilute solutions, whereas in concentrated sulutions the selectivity sequence is reversed. The phenomenon is attributed to the differences in physico-chemical p...

The present article reports on the application of modified organo nanoclay as a green, easily prepared and stable solid sorbent for the preconcentration of trace cobalt ion in aqueous solution. The organo nanoclay was modified by adsorption of 5-(4-dimethyl amino-benzylidene) rhodanin reagent onto it. The sorption of Co2+ ions was quantitative in the pH range of 7.0 to 8.5, whereas quantitative...

Pentafluorophenylboron-capped iron and cobalt(II) hexachloroclathrochelate precursors were obtained by the one-pot template condensation of dichloroglyoxime with pentafluorophenylboronic acid on iron and cobalt(II) ions under vigorous reaction conditions in trifluoroacetic acid media. These reactive precursors easily undergo nucleophilic substitution with (per)fluoroarylthiolate anions, giving ...

The trinuclear title compound, [Co(3)(CH(3)COO)(4)(C(20)H(22)N(2)O(6))(2)]·2CH(2)Cl(2), contains mixed-valence cobalt ions in the following order Co(III)-Co(II)-Co(III) where all the three cobalt ions are hexa-coordinated. The central cobalt ion is situated on an inversion centre and is in an all-oxygen environment, coordinated by four phenolate O atoms and two O atoms from bridging acetate gro...

A simple, highly sensitive, accurate and selective method for determination of trace amounts of Co(II) in water samples is presented. Isocyanate treated graphite oxides (iGOs) solid phase extraction adsorbent was synthesized by covalently isocyanate onto the surfaces of graphite oxides. The stability of a chemically (iGOs) especially in concentrated hydrochloric acid which was then used as a re...

A simple, highly sensitive, accurate and selective method for determination of trace amounts of Co(II) in water samples is presented. Isocyanate treated graphite oxides (iGOs) solid phase extraction adsorbent was synthesized by covalently isocyanate onto the surfaces of graphite oxides. The stability of a chemically (iGOs) especially in concentrated hydrochloric acid which was then used as a re...

the nitrite ® nitro isomerization in nitritopentaamine cobalt (iii) halides has been known. in this paper, the effect of the size of the counter ions (noncoordinated groups) on the rate of isomerization in nitritopentaamine cobalt (iii) halides, is reported. the rate of isomerization is decreased by increasing the size of the counter ions. this decrease is explained on the basis of steric inter...

A classification of kinetics of metalloporphyrin formation is presented according to the composition of the activated complex involved in the reaction. In the reaction of large metal ions, such as mercury(II) and cadmium(II) with porphyrins, these metal ions can not fit into the porphyrin nucleus and they are out—of-plane in the metalloporphyrin. In this case the reaction is relatively fast and...

a simple, highly sensitive, accurate and selective method for determination of trace amounts of co(ii) in water samples is presented. isocyanate treated graphite oxides (igos) solid phase extraction adsorbent was synthesized by covalently isocyanate onto the surfaces of graphite oxides. the stability of a chemically (igos) especially in concentrated hydrochloric acid which was then used as a re...

A thermodynamic study on the interaction of bovine carbonic anhydrase II, CAII, with cobalt(II) and iron(III) ions was made using isothermal titration calorimetry (ITC) at 300.15 K and 310.15 K in Tris buffer solutions at pH = 7.5. The enthalpies of interaction of Co2++ CAII and Fe3++ CAII are reported and analyzed in terms of the extended solvation theory. The results indicate that there are t...